Re: Can I run an app without GUI on Native SDK for BB 10?

While a running app is able to launch other processes with no UI (e.g. via a spawn/exec type of call), the parent process does have to be an app with a UI, launched by the user by tapping on the screen or in response to an invocation request from another app.

There are certain special cases where the app may not actually have a UI open up, though aside from system apps then only case I know of is with the Push Service.

Might be best if you were to describe your use case for this, so someone could give you an answer more specific to your situation.

Re: Can I run an app without GUI on Native SDK for BB 10?

You can try experimenting with extendTerminationPeriod() method of Application class but I think this will be abuse of it's intended purpose. Application will have to be started as GUI application anyway.

Re: Can I run an app without GUI on Native SDK for BB 10?

It is not currently possible with the BB10 APIs. Maybe in future, but we'd been told in the fall it would not be available to third-party devs at launch, though presumably some time after it would be.

The termination-timeout extension idea is a cute one :-) but is unlikely to work. Someone told me with the latest release they changed that so you could ask for only a single extension, and not repeated ones as you could before.

What you can do for now is have the user run your app and just leave it running. There are settings that will allow you to request that geolocation updates continue even when your app is not fullscreen, and even when the device is in "standby", though the app does have to be left active. Once the user exits an app, you have no way to "stay running", for now.